Air travel across the US faces major disruptions on Wednesday as multiple air traffic control alerts force slowdowns at airports nationwide 

The Federal Aviation Administration (FAA) issued flow control alerts, citing equipment problems affecting multiple control centers.

The FAA is managing air traffic flow, a process known as metering flights, to avert congestion and accidents as engineers address the equipment issues.

Some flights could be delayed by more than five hours, while others may face only a few minutes. 

Major US hubs, including New York, Los Angeles, Chicago, Denver, Atlanta and Miami, have been listed as being impacted.

The warnings, identified as FCAGD1 and FCAGD3, apply to almost all flights from ground level up to 60,000 feet, impacting both domestic and international travel until at least 7:59 PM ET.

FCAGD1 is resulting in the most significant delays, averaging over two hours, whereas FCAGD3 is less disruptive, with most delays being only a few minutes, peaking at 15 minutes.

The disruptions come as airports face staff shortages amid the government shutdown, forcing major air traffic control towers to go dark and flight delays.

Some flights could be delayed by more than five hours, while others may face shorter delays of a few minutes (STOCK)

Flights are being rerouted or held on the ground, and airlines including Delta, American, and United are reporting major scheduling disruptions. 

The FCAGD1 alert imposes heavy restrictions, allowing as few as five to 17 flights per hour.

And FCAGD3 appears to manage lighter traffic, permitting seven to 14 flights per hour with average delays of three minutes and a maximum of 15 minutes. 

The FAA’s Unified Delay Program (UDP) and Delay Assignment System (DAS) are now in effect, designed to manage the crisis until full functionality returns.

UDP is used to slow down flights entering busy or affected airspace, limiting the number of planes that can take off or enter specific areas each hour to prevent congestion and accidents.

The FAA deploys DAS to assign specific delays to flights by communicating to airlines when their planes can take off or enter controlled airspace.

This allows flights to be spaced out safely while equipment issues are fixed.

The equipment issues have also impacted several Canadian airports, such as Toronto, Vancouver, Calgary, Montreal and Ottawa.

Major US hubs, including New York, Los Angeles, Chicago, Denver, Atlanta and Miami, have been affected (STOCK)

While the alerts have cited equipment malfunctions, many US airports have been disrupted in the past few days, as air control staff are calling out sick during the government shutdown.

On Tuesday, Nashville International Airport’s (BNA) air control tower went dark for five hours because there was no one available to direct planes.

According to the FAA’s website, the ground delay had backed flights up by more than two hours at the airport.

BNA noted that the FAA told officials this reduction in manpower would ‘remain in effect until further notice.’

A dozen facilities saw staffing shortages on Monday, including Newark Liberty International Airport in New Jersey, where Transportation Secretary Sean Duffy claimed that many air traffic control workers were calling out sick.

‘If we see there are issues in the tower that are affecting controllers’ ability to effectively control the airspace, we’ll reduce the rate, and you’ll see more delays or you might see a cancellation,’ Duffy said.

Chicago’s O’Hare International Airport also endured a travel nightmare on Tuesday due to the government shutdown, which started at 7pm ET and ran until midnight.

O’Hare is one of the busiest airports in the US and the world, handling over 80 million passengers annually and thousands of flights daily. 

Despite the traffic snags, about 92 percent of the more than 23,600 flights departing from US airports as of Tuesday afternoon took off on time, according to aviation analytics firm Cirium.